Due to optical wireless link power budget considerations, the receiver is required to have a large collection area. One of the main noise mechanisms in wideband preamplifiers employing large area detectors is the noise due to the low pass filter formed by the detector capacitance and the input impedance to the preamplifier. Typical large photodetection area commercial detectors has capacitance are around 100-300 pF compared to 50pF in fiber link. Hence, techniques to reduce the effective detector capacitance are required in order to achieve a low noise and wide bandwidth design. In this paper analysis on the bootstrap transimpedance amplifier (BTA) for input capacitance reduction is reported. This technique offers the usual advantages of the transimpedance amplifier together with an effective capacitance reduction technique for optical wireless detector.
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